Decor laminate board generally comprises a laminate containing or coated with a hardenable synthetic resin as will be described in greater detail hereinafter and is generally provided along a face of the board with embossing, texture or other structure imparted in the pressing operation.
The laminate can be inserted into a press in the open condition thereof between press platens which can be provided with embossing surfaces, the press can be closed to apply heat and pressure to the laminate, effect the embossing and cause hardening of the laminate into the board. The press is then opened and the board is removed. A charging device can insert the laminate into the press and a discharging device can remove the board from the press.
Two boards can be made simultaneously in the press by forming a stack of two such laminates having a separating layer to which the laminates are not adherent, between them. The separating layer can be sprayed or applied as a foil between the laminates. The two boards are thus formed on opposite sides of the separating layer and, upon removal from the press, can be destacked so that the stack is separated into its components, namely the two boards and the separating layer.
A laminate stack of this type has not, to the best of my knowledge, been used heretofore in conjunction with a single-level platen press. Rather such stacks are known for the production of decor laminate board in multilevel platen presses which have a number of press openings separated by respective platens and into each of which a respective stack can be introduced.
Multilevel platen presses operate in conjunction with press charging devices and press emptying devices or discharging devices of a type similar to those used with the multilevel presses for the production of particle board, fiber board and the like.
The laminates generally are assembled from intermediate layers of so-called kraft papers while the decor or patterned structure is applied to so called overlays which can overlie the kraft paper layers. The kraft paper layers may be synthetic resin impregnated special papers which can be assembled in a plurality of layers and covered by the overlay which can be a synthetic resin foil.
The laminate is subjected in the press to heat and pressure which, compacts the laminate, imparts a complementary structure of the embossing surface to the contacting face of the laminate and hardens the laminate into a board.
The fabrication of such pattern board in multilevel presses limits the ability for pattern changeover when, for example, frequent changeover is required for small lots of different structured boards. Rapid changeover of the embossing plates is economical only with single-level platen presses.
Both single-level platen presses and multilevel platen presses are cycled and thus can be collectively referred to as cycling presses. It is also known to produce decor laminate board with continuously operating presses, for example, steel belt presses in which the embossing pattern or structure must be provided on a steel belt. Replacement of such belts is time consuming and difficult and the use of these presses is not economical when small lots of the decor laminate board are desirable or when frequent changes of the embossing surfaces from lot to lot is required.
By contrast with multilevel presses, moreover, single-level presses operate in a short cycle process, a technology which is similar to that which has been developed for the laminating of decorative layers onto chip board, fiber board, or for the facing thereof.
Single-level presses require special charging devices like, for example, clamping bar systems (see German Patent Document DE 22 09 901) and emptying devices (see German Patent Document 19 11 764) operating, for example, with suction lifters. Such arrangements are not suitable for the simultaneous production of two decor laminate boards from two laminates in a single operation of a single-level platen press because problems arise in the pressing of such laminates when a separating layer is provided between them. These problems are associated with a tendency of the boards to shift relative to one another when the press is opened or as the press is opened, thereby making the removal of the boards difficult, if not impossible.